Platelet hyperreactivity after coronary artery bypass grafting: the possible relevance to glycoprotein polymorphisms. A preliminary report.

Coronary artery bypass grafting (CABG) surgery impairs platelet function and reactivity to a considerable extent. However, variability in the individual patients' responses makes any generalised statement uncertain. The observed variability is nowadays thought to relate to platelet glycoprotein polymorphisms. Our objective was to investigate the association between platelet reactivity and the restoration of platelet functional response to agonists during the period following cardiosurgical operation and some genetic polymorphisms of selected platelet membrane glycoproteins. Platelet reactivity was monitored in 32 IHD patients (56 +/- 8 years) subjected to CABG surgery by means of whole blood impedance aggregometry and concurrently using the platelet function analyser (PFA-100 at four time intervals: prior to operation (A), 2 h after administration of protamine sulfate (B), 3 days after (C) and 7 days after CABG surgery (D). Three important findings were made. First, in all patients platelet reactivity became decreased 2 h postoperatively (aggregation with 20 microM ADP reduced by up to 49%, P < 0.02) and vastly increased 7 days after CABG surgery (CT(CADP) reduced down to 87% of initial value, P < 0.05, ADP-induced aggregation enhanced up to 167%, P < 0.001, and that with collagen up to 131% of the initial value, P < 0.01). Second, the frequencies of the 'prothrombotic' phenotype variants of platelet membrane glycoproteins were higher in patients referred to as the carriers of more reactive platelets compared to those with less reactive platelets (GPIa (807)T-positive, 50 vs. 28%; GPIIIa Pl(A2)-positive, 27 vs. 21%; GPIb Met(145)-positive and GPIb VNTR B-positive, 13 vs. 0%. Lastly, the restoration in platelet hyperreactivity in CABG surgery patients was recorded more often in patients who underwent postoperative myocardial ischaemic episode(s), and was associated with significantly higher frequency of the 'prothrombotic' allele (807)T of the collagen receptor glycoprotein Ia (GPIa) in these subjects (83 vs. 61%). In conclusion, in patients with ischaemic episodes after CABG, we demonstrated a fast postoperative restoration of haemostatic capacity and evidence of platelet hyperreactivity at 7 days after CABG surgery. The platelet hyperfunction seems to relate to the occurrence of platelet glycoprotein polymorphisms GPIa(807)C/T and GPIIIa PlA(1/A2) and may be important in predicting postoperative vascular complications in CABG patients.

Activation of blood platelets after percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery.

We have evaluated the activation of platelets in blood samples taken from patients with stable angina undergoing balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) (n=11) or coronary artery bypass grafting (CABG) under hypothermic (n=11) or normothermic conditions (n=11). We have found that surface expression of P-selectin on platelets in whole blood from PTCA patients upon thrombin treatment was significantly reduced, as compared with control platelets from healthy subjects. This effect was partially reversed when platelets washed from the same blood sample were used, but even then P-selectin expression was significantly lower in PTCA patients than it was in control subjects. There was a significant increase in basal expression of P-selectin in blood platelets taken from patients who underwent CABG under normothermic conditions (warm blood cardioplegia) as opposed to hypothermic patients (cold crystalloid cardioplegia). These platelets retain the ability to respond to agonists, although to a much lower extent than do those from healthy control donors. The surface exposure of P-selectin on resting and thrombin-treated platelets isolated from CABG surgery patients was not different from that of the control platelets. The adhesion to fibrinogen of resting and thrombin-treated platelets from patients who underwent balloon angioplasty as well as CABG surgery under normothermic and hypothermic conditions was significantly reduced when compared with the fibrinogen of the control platelets. These results suggest that the function of platelet fibrinogen receptor is impaired in patients with stable angina pectoris and that PTCA and CABG surgery activates platelets.

[The effects of coronary artery bypass grafting in men under the age of 45]. / Wyniki pomostowania tetnic wiencowych u mezczyzn do 45 roku zycia.

In Poland young and middle-aged men are a population at risk of premature development of ischemic heart disease (IHD). This prospective study was designed in order to estimate the effects of coronary artery bypass grafting (CABG) on survival and quality of life in this population. 60 men aged (mean&SD) 41 +/- 3.2 years, operated on in 1993 at the Department of Cardiosurgery, Medical University of Lódz, were enrolled into the study. The study protocol included two postoperative follow-up examinations: after 2 and 5 years. A perioperative mortality rate was 3.3%, 2-years survival rate 92% and 5-years one 87%. Asymptomatic survival rates were 75% et 44%, respectively. During the first follow-up examination a significant improvement of exercise performance compared with preoperative period, was observed. However, at the same time there was no improvement in left ventricular function, measured as its ejection fraction in echocardiography. The effects of CABG procedure on risk factors control, medical treatment and professional activity were also analysed. The long-term results of CABG operations in young men, as far as survival rates are concerned, are good. However, the longer follow-up period was analysed the less beneficial influence of the operations on patients' clinical state and quality of life was observed.

Low doses of aprotinin in aortocoronary bypass surgery--advantages and disadvantages.

INTRODUCTION: Excessive blood loss, as a result of augmented postoperative drainage, is considered one of the most serious cardiosurgical complications. The compounding constitutive anemia seems particularly harmful for patients with coronary artery disease. Aprotinin (Trasylol), a non-specific serine protease inhibitor, is successfully used to reduce excessive postoperative bleeding in such patients. The aim of our study was to verify the hypothesis whether aprotinin used during cardiopulmonary bypass procedure affects hemostatic parameters, which might be crucial for the elevated risk of thromboembolic complications. MATERIAL AND METHODS: The group of 54 patients subjected to coronary artery surgical treatment included 30 patients, who were given intraoperatively 3 million KIU aprotinin each, and 24 subjects non-treated with aprotinin. Aliquots of blood were withdrawn at several time intervals, until the 5th day after the operation. Whole blood platelet activation and reactivity (the expressions of P-selectin and glycoprotein Ib) were monitored by means of flow cytometry. In addition, several plasma parameters, like PAI-1, t-PA, D-dimers, prothrombin fragment F1 + 2, fibrinogen, ATIII activity, troponin I and CK-MB, as well as platelet count were determined at each time point. RESULTS: In this study we confirmed the essential advantage of the use of aprotinin: both the postoperative blood drainage and the blood units to be transfused postoperatively to cardiosurgical patients were vastly reduced in the aprotinin-treated subjects. The enhanced overall frequency of perioperative myocardial infarction events was not attributed to this group of patients, nor the non Q-wave infarctions were observed more often in patients treated with aprotinin. In these patients, fibrinolysis parameters tended to be depressed (with increased PAI-1 dominating over elevated t-PA) on the first day after the operation, and no significant differences with regard to fibrinogen, prothrombin fragment F1 + 2, troponin I and platelet count. There was a continuous rise in D-dimers in all the postoperative patients, which lasted until the third day and tended to reach plateau at the 5th day after the operation. We failed to reveal the preventive effects of aprotinin on platelet function: both platelet activation and reactivity remained apparently unchanged. Overall, our results rather support the reasoning on the advantageous effects of low doses of aprotinin. The use of this inhibitor reduces the risk of postoperative undesirable bleeding and results in a decreased postoperative drainage and reduced transfused blood units. On the other hand, however, a higher incidence of perioperative Q-wave infarction in the aprotinin-treated patients, although purely apparent and not statistically significant, might question the unlimited safety of the use of aprotinin in cardiovascular operations.

Moderate systemic hypothermia and cold crystalloid cardioplegia influence on myocardial ischemic and revascularisative injury.

The number of granulocytes, their ability to generate superoxide anion (O2-) and the activities of Cu, Zn--superoxide dismutase (SOD-1), glutathione peroxidase (GSH-Px), catalase (CAT) as well as malonyldialdehyde (MDA) concentrations in erythrocytes in the blood extracted from the venous sinus and aorta under coronary artery bypass were examined with the use of St. Thomas Hospital cardioplegic solution. Specimens at the peak of ischemia of the right atrium for ultrastructural examination of the endothelial cells of capillary vessels and sarcomers were taken. The blood was obtained during cardiopulmonary bypass (CPB) before the aorta clamping and immediately after aorta declamping (peak of ischaemia) between 1-3 minute and 10-13 minute of reperfusion. Increase of the number of granulocytes both in the coronary sinus and aortal blood at all examined intervals as well as decrease in the number of ones in sinus compared with aortal blood was noted. The ability to produce superoxide anion radical decreased at the peak of ischemia and during reperfusion. The activity of SOD-1 was lower both after the period of ischemia and reperfusion. The increase in aortal blood activity during reperfusion was characteristic of GSH-Px; the activity was higher in the blood sample from the coronary sinus taken during ischemia and initial reperfusion. With the exception of the initial reperfusion the activity of CAT diminished in all observed cases. MDA concentration did not demonstrate any significant changes with the exception of the initial reperfusion in the aortal blood and later towards the end of reperfusion in the blood from the coronary sinus. Ultrastructural studies indicated overhydration of the cells both in the endothelium and the intercellular space. The obtained data demonstrate that the applied cardioplegic solution protects the myocardium from harmful effects of reactive oxygen species produced as a result of ischemia and reperfusion.

[Myocardial revascularization for sudden cardiac death in patients after previous coronary angioplasty]. / Rewaskularyzacja serca w trybie naglym u chorych po przebytej koronaroplastyce.

UNLABELLED: PTCA was introduced into our hospital in June 1991. Since then till the end of 1996 emergency CABG operations were performed in fourteen patients. They were indicated because of acute myocardial ischaemia and hemodynamic deterioration that was the result of the dissection and occlusion of a coronary artery during angioplasty. There were 11 male and 3 female patients in this group aged 34 to 65 average 50 years. Twenty-three grafts were performed in total (18 saphenous, 5 using internal mammary artery), that is 1.6 graft per patient. A female patient died of myocardial infarction on the first postoperative day. All other patients survived and are under outpatient clinic's care. Over the analysed 6 years' period of time 1079 PTCAs were performed. The low rate of the unsuccessful procedures (1.3%) that required the emergency CABG is noteworthy. Since 1995, when the implantation of stents was introduced into our hospital, there were only 2 such procedures (0.4% of all PTCAs). CONCLUSIONS: The CABG operation performed shortly after a dissection and occlusion of the coronary artery underwent angioplasty usually prevents myocardial infarction and saves the patient's live. The introduction of implantation of the stents significantly diminished a number of patients who required an emergency CABG operation.

[Metabolic changes in blood oxygen in the human heart under ischemic and reperfusion conditions]. / Zmiany metabolizmu tlenowego krwi z serca ludzkiego w warunkach niedokrwienia i reperfuzji.

The number of granulocytes, their capability to generate O2-. and the activity of SOD-1, GSH-Px, Cat as well as MDA concentrations in erythrocytes in the blood extracted from the venous sinus and aorta under coronary artery bypass with use of St. Thomas cardioplegic solution were determined. The blood for examination was obtained before the institution of cardiopulmonary bypass, in the period of the deepest ischaemia (just after declamping of the aorta) and between the 1-3 minute and the 10-13 minute of reperfusion. A rise in the number of granulocytes both in the venous sinus and aortal blood at all examined intervals was noted. Capability to produce superoxide anion radicals decreased at the peak of ischemia and during reperfusion. The activity of SOD-1 was lower both after the period of ischemia and reperfusion. A rise in aortal blood activity during reperfusion was characteristic for GSH-Px; the activity was greater in the blood sampled from the coronary sinus during ischemia and initial reperfusion. With the exception of the initial reperfusion the activity of Cat diminished in all observed cases. We did not observe any significant changes in MDA concentration with the exception of the initial reperfusion in the aortal blood and later during reperfusion in the blood from the coronary sinus. The results demonstrate that the applied cardioplegic solution may protect myocardium from harmful effects of active oxygen froms produced as a results of ischemia and reperfusion.

[Minutiae of skin ridges in Down's syndrome]. / Minucje listewek skórnych w zespole Downa.

Minutiae of the epidermal ridges were examined in 16 children with Down's syndrome and 50 children without genetic and familial abnormalities. Minutiae in standard areas on the hand palms (according to Grzeszyk's concept) were examined. Comparative analysis confirmed by the statistical analysis showed significant differences in the incidence of particular minutiae types on the hand palms of children with Down's syndrome and control group.

[Results of the treatment of patent ductus arteriosus]. / Wyniki leczenia przetrwalego przewodu tetniczego.

Since the first effective surgical treatment of PAD, the indications for such a treatment have been more extensive and its results and methods have been changing. We present 123 patients who underwent surgery for PAD in the Clinic of Cardiosurgery, Institute of Cardiology, Medical Academy of Lódz within 1978-1987. In 101 cases PAD was dissected and both ends were sutured in two layers with continuous sutures, and in 22 cases PAD was ligated with 3 ligatures. In 30 patients PAD coincided with other congenital defects of the circulatory system. No cases of recanalization were observed in our patients. One death in the postoperative course was noted.

[Personal observations of dobutamine effectiveness after surgery with extracorporeal circulation]. / Wlasne spostrzezenia w stosowaniu dobutaminy po operacjach w krazeniu pozaustrojowym.

This report describes the use of dobutamine in patients presenting a low output syndrome after cardiosurgical operations i EEC. Of 565 patients operated on valvular heart defects and coronary artery disease in 89 patients (15.7%) a low output syndrome was diagnosed and treated. Dobutamine proved to be effective in patients with moderate impairment of the left ventricular contractility. In those with severe left ventricular dysfunction, dobutamine was ineffective and other catecholamines ought to be used. The authors support the view that combined administration of dobutamine (or other catecholamines) and nitroglycerin in patients with low output syndrome proves to be superior to the effect of each single drug.